Excision repair cross-complementation group 1 predicts progression-free and overall survival in non-small cell lung cancer patients treated with platinum-based chemotherapy

Thioredoxin System Protein Expression in Carcinomas of the Pancreas, Distal Bile Duct, and Ampulla in the United Kingdom

Background: Poor survival outcomes in periampullary cancer highlight the need for improvement in biomarkers and the development of novel therapies. Redox proteins, including the thioredoxin system, play vital roles in cellular antioxidant systems. Methods: In this retrospective study, thioredoxin (Trx), thioredoxin-interacting protein (TxNIP), and thioredoxin reductase (TrxR) protein expression was assessed in 85 patients with pancreatic ductal adenocarcinoma (PDAC) and 145 patients with distal bile duct or ampullary carcinoma using conventional immunohistochemistry. Results: In patients with PDAC, high cytoplasmic TrxR expression was significantly associated with lymph node metastasis (p = 0.033). High cytoplasmic and nuclear Trx expression was significantly associated with better overall survival (p = 0.018 and p = 0.006, respectively), and nuclear Trx expression remained significant in multivariate Cox regression analysis (p < 0.0001). In distal bile duct and ampullary carcinomas, high nuclear TrxR expression was associated with vascular (p = 0.001) and perineural (p = 0.021) invasion, and low cytoplasmic TxNIP expression was associated with perineural invasion (p = 0.025). High cytoplasmic TxNIP expression was significantly associated with better overall survival (p = 0.0002), which remained significant in multivariate Cox regression analysis (p = 0.013). Conclusions: These findings demonstrate the prognostic importance of Trx system protein expression in periampullary cancers.

Expression patterns and prognostic significances of RRM1 and ERCC1 in pancreatic carcinoma and cholangiocarcinoma

BACKGROUND

Aggressive pancreatobiliary tumors often require oxaliplatin-based therapies, instead of standard gemcitabine-based therapy and biomarker studies at diagnosis to decide the appropriate therapeutic regimen. The ribonucleotide Reductase catalytic subunit M1 (RRM1) and excision repair cross-complementing gene-1 (ERCC1) are related to DNA synthesis and repair and essential in this regard. However, apart from the therapeutic benefit, their prognostic implication is controversial.

METHODS

In this retrospective study, paraffin-embedded tissue from 51 cases of pancreatic cancer and 29 cases of cholangiocarcinoma were evaluated for RRM1 and ERCC1 expression by immunohistochemical technique along with 18 control pancreatic and biliary tissues. The semiquantitatively H score was calculated based on stain distribution and stain intensities.

RESULTS

Both RRM1 and ERCC1 expression were high in tumor epithelium than in controls (RRM1: the difference was statistically significant in cholangiocarcinoma (P = 0.008); ERCC1: the difference was statistically significant both in pancreatic and cholangiocarcinoma (P < 0.05)]. However, no correlation was noted between RRM1 and ERCC1-low and high tumors with histological markers of prognosis and overall survival in these patients.

CONCLUSIONS

The present study adds further evidence against the controversy that if RRM1 and ERCC1 expression in pancreatic and biliary carcinomas have any prognostic significance apart from their proven therapeutic benefits in these tumors.

The ZEB2-dependent EMT transcriptional programme drives therapy resistance by activating nucleotide excision repair genes ERCC1 and ERCC4 in colorectal cancer

Resistance to adjuvant chemotherapy is a major clinical problem in the treatment of colorectal cancer (CRC). The aim of this study was to elucidate the role of an epithelial to mesenchymal transition (EMT)‐inducing protein, ZEB2, in chemoresistance of CRC, and to uncover the underlying mechanism. We performed IHC for ZEB2 and association analyses with clinical outcomes on primary CRC and matched CRC liver metastases in compliance with observational biomarker study guidelines. ZEB2 expression in primary tumours was an independent prognostic marker of reduced overall survival and disease‐free survival in patients who received adjuvant FOLFOX chemotherapy. ZEB2 expression was retained in 96% of liver metastases. The ZEB2‐dependent EMT transcriptional programme activated nucleotide excision repair (NER) pathway largely via upregulation of the ERCC1 gene and other components in NER pathway, leading to enhanced viability of CRC cells upon oxaliplatin treatment. ERCC1‐overexpressing CRC cells did not respond to oxaliplatin in vivo, as assessed using a murine orthotopic model in a randomised and blinded preclinical study. Our findings show that ZEB2 is a biomarker of tumour response to chemotherapy and risk of recurrence in CRC patients. We propose that the ZEB2‐ERCC1 axis is a key determinant of chemoresistance in CRC.

The prognostic value of excission repair cross-complementation group one enzyme expression in locally advanced cervical carcinoma patients treated with cisplatin-based treatment: a meta-analysis

BACKGROUND

Recently, several studies observed that locally advanced cervical carcinoma with negative excision repair crross-complementation group one enzyme expression has better outcomes in cisplatin-based chemotherapy or chemoradiotherapy than carcinoma with positive excission repair cross-complementation group one enzyme expression. In this meta-analysis, we quantitatively evaluated the prognostic value of excission repair cross-complementation group one enzyme expression in locally advanced cervical carcinoma patients receiving platinum-based chemotherapy or chemoradiotherapy.

MATERIALS

A systematic search for relevant studies was conducted in the PubMed, Cochrane Library, EMBASE and Medline databases. Fixed- or random-effects models were used for pooled analysis. The endpoints were overall survival and disease-free survival () reported as ORs and 95% CIs. The effects of excission repair cross-complementation group one enzyme expression on the clinicopathological parameters were measured by the pooled ORs and their 95% CIs.

RESULTS

Eight studies (612 patients in total) satisfied the inclusion criteria. Negative/low excission repair cross-complementation group one enzyme expression was significantly associated with better overall survival (OR, 1.92; 95% CI, 1.22 to 3.05; P = 0.005) and disease-free survival (OR, 5.77; 95% CI, 1.90 to 17.54; P = 0.002). Additionally, there were significant associations between excission repair cross-complementation group one enzyme expression and lymph node metastasis (OR, 2.57; 95% CI, 1.28 to 5.16; P = 0.008).

CONCLUSIONS

This meta-analysis suggested that pretreatment excission repair cross-complementation group one enzyme expression might be a useful biomarker to predict prognoses for locally advanced cervical carcinoma patients receiving platinum-based chemotherapy or chemoradiotherapy.

Expression of MRP1, BCRP, LRP and ERCC1 as prognostic factors in non-small cell lung cancer patients receiving postoperative cisplatin-based chemotherapy

The development of resistance to chemotherapy is one of the major obstacles in the treatment of non-small cell lung cancer (NSCLC). The purpose of this study was to investigate the prognostic value of multidrug resistance protein 1 (MRP1), breast cancer resistance protein (BCRP), lung resistance-related protein (LRP), and excision repair cross-complementing 1 (ERCC1) in NSCLC patients receiving cisplatin-based adjuvant chemotherapy (cisplatin plus vinorelbine or gemcitabine) after tumor resection. We used semiquantitative reverse-transcription polymerase chain reaction to detect the expression of MRP1, BCRP, LRP and ERCC1 mRNA in surgical resection specimens of 60 patients with stage IB through IIIA NSCLC. The expression level of each gene was analyzed in relation to clinicopathological factors, tumor-free survival (TFS), and overall survival. The results showed that stage IIIA (p=0.011), N1 and N2 status (p=0.008), high expression of MRP1 (p=0.034) and LRP (p=0.018) were associated with shorter TFS. Stage IIIA (p=0.0105), N1 and N2 status (p=0.009), high expression of MRP1 (p=0.021) and ERCC1 (p=0.012) were related to a shorter overall survival. Cox multivariate analyses revealed that early stage (p=0.013 and p=0.024), negative lymph node status (p=0.006 and p=0.011), and low MRP1 expression (p=0.022 and p=0.035) were independent predictors of favorable TFS and overall survival, respectively. Additionally, ERCC1 (p=0.019) was an independent predictor of favorable overall survival.

ERCC1_202 Is A Prognostic Biomarker in Advanced Stage Non-Small Cell Lung Cancer Patients Treated with Platinum-Based Chemotherapy

Purpose: To develop a qPCR method to examine the 202 isoform of excision repair cross-complementation group 1 (ERCC1_202) and to evaluate its clinical utility as a predictive biomarker for platinum-based chemotherapy in non-small cell lung cancer (NSCLC). Methods: The relative complementary DNA (cDNA) quantification for ERCC1_202 was conducted using a fluorescence-based, real-time detection method and β-actin was used as a reference gene. Results: A strong correlation was observed between ERCC1_202 mRNA and ERCC1 mRNA levels in NSCLC cells (P < 0.001). 28 patients completed this research. Our results implied that as ERCC1_202 levels increased, the risk of progression (HR = 4.296, P = 0.011) and death (HR = 6.503, P = 0.001) increased. At multivariate analysis, high expression of ERCC1_202 was shown to be an independent predictive factor for time to progression (P = 0.047), and progression-free survival (P = 0.014). However, the high expression of ERCC1_202 was not an independent predictive factor for response (P = 0.324). Conclusions: This study suggests that the efficacy of platinum-based chemotherapy can be improved when customized according to the expression of ERCC1_202.

Combined Ki67 and ERCC1 for prognosis in non-keratinizing nasopharyngeal carcinoma underwent chemoradiotherapy

This study aimed to assess the predictive value of combined Ki67 and ERCC1 in distant metastasis-free nasopharyngeal carcinoma. 334 such cases were retrospectively assessed. Immunohistochemistry was used to evaluate Ki67 and ERCC1 protein levels in tumor tissues. Associations of Ki67 and ERCC1 amounts with clinical characteristics and survival were analyzed. Medium follow-up was 48.7 months; overall survival (OS), disease-free survival (DFS), distant metastasis-free survival (DMFS), and local recurrence-free survival (LRFS) were 91.3%, 76.0%, 82.0%, and 91.9%, respectively. High Ki67 expression was found in 35.6% patients, and positively correlated with clinical- and N- staging (P = 0.005, P < 0.001); 4-year OS, DFS, and DMFS were significantly lower in the high Ki67 group than patients with low-medium expression (P = 0.001, P = 0.012, P = 0.007). High ERCC1 expression was found in 35.3% of patients, and positively correlated with clinical- and T- staging. Compared with low ERCC1 expression cases, 4-year OS, DFS, DMFS, and LRFS were decreased significantly in those with high levels. High Ki67 and ERCC1 levels were related to adverse prognoses of OS (HR=4.977, 95% CI 2.31–12.292, P<0.001), DFS (HR = 4.178, 95% CI 2.421–7.212, P < 0.001), DMFS (HR = 3.722, 95% CI 2.028–7.015, P < 0.001), and LRFS (HR = 3.689, 95% CI 1.423–9.566, P = 0.007). Compared with the low-medium Ki67 and low ERCC1 groups, no significant difference in survival prognosis was obtained in the low-medium Ki67 and high ERCC1 groups, and patients with high Ki67 and low ERCC1 levels. Combined Ki67 and ERCC1 can better predict nasopharyngeal carcinoma prognosis than individual parameters.

Chemosensitizing effect of shRNA-mediated ERCC1 silencing on a Xuanwei lung adenocarcinoma cell line and its clinical significance

Lung cancer is a common fatal malignancy in both men and women. Xuanwei, Yunnan has the highest incidence of lung cancer in China. The area has a specific risk factor in the domestic combustion of bituminous coal, and lung cancer patients from this area tend to be resistant to platinum-based treatments. However, little is known about the mechanism of platinum resistance in patients from Xuanwei. Herein, we used lentiviral infection with shRNA to silence expression of the DNA repair enzyme ERCC1 in XWLC05 both in its RNA and protein expression level, a lung adenoma cell line derived from a patient from Xuanwei. ERCC1 expression in this cell line is high and contributes to its resistance to cisplatin. Suppression of ERCC1 decreased XWLC05 proliferation in vitro (IC50 of cisplatin 1.34 µM for shRNA-infected cells vs. 4.54 µM for control cells) and increased the apoptotic rate after treatment with cisplatin (81.2% shRNA cells vs. 58% control cells, P<0.05). Progression-free survival was longer in ERCC1-negative lung adenoma patients than those with high ERCC1 levels (30 vs. 11 months, P<0.0001). ERCC1 expression was identified as a prognostic marker for overall survival in the patient cohort with operable lesions. Taken together, our data identify ERCC1 as a disease marker in lung adenoma patients from Xuanwei and confirm the significance of resection for the subsequent effect of platinum treatment in these patients. Additional studies are needed to determine the mechanism of ERCC1-induced platinum resistance in lung adenoma patients from Xuanwei.

Serum proteomic test in advanced non-squamous non-small cell lung cancer treated in first line with standard chemotherapy

BACKGROUND

VeriStrat is a blood-based proteomic test with predictive and prognostic significance in second-line treatments for non-small cell lung cancer (NSCLC). This trial was designed to investigate the role of VeriStrat in first-line treatment of advanced NSCLC with standard chemotherapy. Here we present the results for 76 non-squamous patients treated with a combination of carboplatin or cisplatin with pemetrexed.

METHODS

The test-assigned classifications of VeriStrat Good or VeriStrat Poor to samples collected at baseline. The primary end point was progression-free survival (PFS); secondary end points included overall survival (OS) and objective response. Exploratory analyses of end points separately in carboplatin/pemetrexed and cisplatin/pemetrexed subgroups were also conducted.

RESULTS

Patients classified as VeriStrat Good had longer PFS and OS than VeriStrat Poor: 6.5 vs 1.6 months and 10.8 vs 3.4 months, respectively; the corresponding hazard ratios (HRs) were 0.36 (P<0.0001) and 0.26 (P<0.0001); they were also more likely to achieve objective response. Prognostic significance of VeriStrat was confirmed in multivariate analysis. Significant differences in OS and PFS between Veristrat classifications were also found when treatment subgroups were analysed separately.

CONCLUSIONS

The trial demonstrated clinical utility of VeriStrat as a prognostic test for standard first-line chemotherapy of non-squamous advanced NSCLC.

Combination gemcitabine/cisplatin therapy and ERCC1 expression for resected pancreatic adenocarcinoma: Results of a Phase II prospective trial

BACKGROUND

Standard adjuvant treatment for pancreatic adenocarcinoma (PDAC) is gemcitabine [Gem(CONKO-001: Gem vs. placebo DFS:13.4 vs. 6.7 mo; P < 0.001; OS:22.8 vs. 20.2 mo; P = 0.01)]. Addition of cisplatin (Cis) to Gem has resulted in increased PFS for advanced and metastatic disease, which may be predicted by low expression of excision repair cross-complementing group-1 (ERCC1), the key enzyme in nucleotide excision repair. This Phase II prospective trial assesses outcomes of patients treated with adjuvant Gem/Cis, stratifying results by tumor ERCC1 expression.

METHODS

Patients with resected PDAC were enrolled (2010-2013) and received Gem(1,000 mg/m(2) )/Cis(50 mg/m(2) ). Tumor ERCC1 expression was evaluated by immunohistochemistry and dichotomized into low or high expression. Primary outcomes were recurrence-free and overall survival (RFS/OS).

RESULTS

Of 22 pts, 16(73%) were Stage IIB, 5(23%) Stage IIA, and 1(4%) Stage IA. Grade 3/4 toxicity occurred in 13 pts (59%); neutropenia was most common (n = 9;41%). Median follow-up was 37.5 months. Median RFS was 16.7 mo; OS was 35.5 mo. Low ERCC1 (n = 15;75%) compared to high ERCC1 (n = 5;25%) was not associated with improved RFS (12.4 vs. 16.7 mo; P = 0.68) or OS (Median not reached vs. 21.6 mo; P = 0.22).

CONCLUSIONS

Adjuvant Gem/Cis is feasible in patients with resected pancreatic adenocarcinoma. RFS and OS for Gem/Cis appear promising compared to historic control. Tumor ERCC1 expression can be reliably evaluated, and low expression is present in most patients. J. Surg. Oncol. 2016;114:336-341. © 2016 Wiley Periodicals, Inc.

Tumor marker analyses from the phase III, placebo-controlled, FASTACT-2 study of intercalated erlotinib with gemcitabine/platinum in the first-line treatment of advanced non-small-cell lung cancer

OBJECTIVES

The FASTACT-2 study of intercalated erlotinib with chemotherapy in Asian patients found that EGFR mutations were the main driver behind the significant progression-free survival (PFS) benefit noted in the overall population. Further exploratory biomarker analyses were conducted to provide additional insight.

MATERIALS AND METHODS

This multicenter, randomized, placebo-controlled, double-blind, phase III study investigated intercalated first-line erlotinib or placebo with gemcitabine/platinum, followed by maintenance erlotinib or placebo, for patients with stage IIIB/IV non-small cell lung cancer (NSCLC). Provision of samples for biomarker analysis was encouraged but not mandatory. The following biomarkers were analyzed (in order of priority): EGFR mutation by cobas(®) test, KRAS mutation by cobas(®)KRAS test, HER2 by immunohistochemistry (IHC), HER3 by IHC, ERCC1 by IHC, EGFR gene copy number by fluorescence in-situ hybridization (FISH) and EGFR by IHC. All subgroups were assessed for PFS (primary endpoint), overall survival (OS), non-progression rate and objective response rate.

RESULTS

Overall, 256 patients provided samples for analysis. Considerable overlap was noted among biomarkers, except for EGFR and KRAS mutations, which are mutually exclusive. Other than EGFR mutations (p<0.0001), no other biomarkers were significantly predictive of outcomes in a treatment-by-biomarker interaction test, although ERCC1 IHC-positive status was predictive of improved OS for the erlotinib arm versus placebo in EGFR wild-type patients (median 18.4 vs 9.5 months; hazard ratio [HR] HR=0.32, 95% confidence intervals [CI]: 0.14-0.69, p=0.0024).

CONCLUSION

Activating EGFR mutations were predictive for improved treatment outcomes with a first-line intercalated regimen of chemotherapy and erlotinib in NSCLC. ERCC1 status may have some predictive value in EGFR wild-type disease, but requires further investigation.

Factors affecting platinum sensitivity in cervical cancer

The present study aimed to investigate the association between nedaplatin (NDP) sensitivity and the expression of biological factors in cervical cancer. A total of 45 cervical cancer specimens, including 18 pretreatment biopsies and 27 surgical specimens, were used in histoculture drug response assays to determine the chemosensitivity of cervical cancer specimens to NDP. Each specimen was assessed for immunohistochemical expression of Ki-67, p53, B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax), cleaved caspase-3, cyclooxygenase-2 (COX-2), and excision repair cross-complementation group 1 (ERCC1). The results revealed that low or negative expression of p53, Bcl-2 and COX-2, and high or positive expression of cleaved caspase-3 were significantly correlated with high sensitivity to NDP. However, there were no significant differences in Ki-67, Bax or ERCC1 expression between the low and high sensitivity groups. These findings indicate that sensitivity to platinum may be easily predicted by immunostaining for the detection of these specific factors in pretreatment biopsies or surgical specimens. The expression profiles of these targets may therefore provide additional information for planning individualized chemotherapy in the treatment of cervical cancer.

Multinational Randomized Phase III Trial With or Without Consolidation Chemotherapy Using Docetaxel and Cisplatin After Concurrent Chemoradiation in Inoperable Stage III Non-Small-Cell Lung Cancer: KCSG-LU05-04

PURPOSE

To determine the efficacy of consolidation chemotherapy (CC) with docetaxel and cisplatin (DP) after concurrent chemoradiotherapy (CCRT) with the same agents in locally advanced non-small-cell lung cancer (LA-NSCLC).

PATIENT AND METHODS

Patients were randomly assigned to either CCRT alone (observation arm) or CCRT followed by CC (consolidation arm). CCRT with docetaxel (20 mg/m(2)) and cisplatin (20 mg/m(2)) was administered every week for 6 weeks with a total dose of 66 Gy of thoracic radiotherapy in 33 fractions. In the consolidation arm, patients were further treated with three cycles of DP (35 mg/m(2) each on days 1 and 8, every 3 weeks). The primary end point was 40% improvement in progression-free survival (PFS) compared with observation.

RESULTS

From October 2005 to April 2011, 437 patients were randomly assigned. Seventeen patients did not start CCRT as a result of consent withdrawal or ineligibility reasons after random assignment, leaving 420 patients for this analysis (n = 211 for observation; n = 209 for consolidation). Patient characteristics were similar in both arms. In the consolidation arm, 143 patients (68%) received CC, of whom 88 (62%) completed three planned cycles. The median PFS was 8.1 months in the observation arm and 9.1 months in the consolidation arm (hazard ratio, 0.91; 95% CI, 0.73 to 1.12; P = .36). Median overall survival times were 20.6 and 21.8 months in the observation and consolidation arms, respectively (HR, 0.91; 95% CI, 0.72 to 1.25; P = .44).

CONCLUSION

CC with DP after CCRT with weekly DP in LA-NSCLC failed to further prolong PFS. CCRT alone should remain the standard of care.

The role of DNA repair pathways in cisplatin resistant lung cancer

Platinum chemotherapeutic agents such as cisplatin are currently used in the treatment of various malignancies such as lung cancer. However, their efficacy is significantly hindered by the development of resistance during treatment. While a number of factors have been reported that contribute to the onset of this resistance phenotype, alterations in the DNA repair capacity of damaged cells is now recognised as an important factor in mediating this phenomenon. The mode of action of cisplatin has been linked to its ability to crosslink purine bases on the DNA, thereby interfering with DNA repair mechanisms and inducing DNA damage. Following DNA damage, cells respond by activating a DNA-damage response that either leads to repair of the lesion by the cell thereby promoting resistance to the drug, or cell death via activation of the apoptotic response. Therefore, DNA repair is a vital target to improving cancer therapy and reduce the resistance of tumour cells to DNA damaging agents currently used in the treatment of cancer patients. To date, despite the numerous findings that differential expression of components of the various DNA repair pathways correlate with response to cisplatin, translation of such findings in the clinical setting are still warranted. The identification of alterations in specific proteins and pathways that contribute to these unique DNA repair pathways in cisplatin resistant cancer cells may potentially lead to a renewed interest in the development of rational novel therapies for cisplatin resistant cancers, in particular, lung cancer.

DNA repair gene associated with clinical outcome of epithelial ovarian cancer treated with platinum-based chemotherapy

OBJECTIVE

The nucleotide excision repair (NER) and base excision repair (BER) pathways, two DNA repair pathways, are related to platinum resistance in cancer treatment. In this paper, we studied the association between single nucleotide polymorphisms (SNPs) of involved genes and response to platinum-based chemotherapy in epithelial ovarian cancer.

METHOD

Eight SNPs in XRCC1 (BER), XPC and XPD (NER) were assessed in 213 patients with epithelial ovarian cancer using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and primer-introduced restriction analysis-polymerase chain reaction (PIRA-PCR) techniques.

RESULTS

The median progression-free survival (PFS) of patients carrying the Lys/Lys and Lys/Gln+Gln/Gln genotype of the XPC Lys/Gln polymorphism were 25 and 12 months, respectively (P=0.039); and the mean overall survival (OS) of patients was 31.1 and 27.8 months, respectively (P=0.048). Cox's multivariate analysis suggested that patients with epithelial ovarian cancer with the Gln allele had an increased risk of death (HR=1.75; 95% CI=1.06-2.91) compared to those with the Lys/Lys genotype. There are no associations between the XPC PAT+/-, XRCC1 Arg194Trp, Arg280His, Arg399Gln, and XPD Asp312Asn, Lys751Gln polymorphisms and the survival of patients with epithelial ovarian cancer when treated with platinum-based chemotherapy.

CONCLUSION

Our results indicated that the XPC Lys939Gln polymorphism may correlate with clinical outcome of patients with epithelial ovarian cancer when treated with platinum-based chemotherapy in Northern China.

Nucleotide excision repair: why is it not used to predict response to platinum-based chemotherapy?

Platinum based therapy is one of the most effectively used chemotherapeutic treatments for cancer. The mechanism of action of platinum compounds is to damage DNA and drive cells into apoptosis. The most commonly used platinum containing agents are cis-diammine-dichloroplatinum (II)], more commonly known as cisplatin, its analogue carboplatin, and oxaliplatin. Cisplatin is used to treat a wide variety of tumours such as ovarian, testicular, head and neck and non-small cell lung cancers (NSCLCs). In addition, it forms the basis of most combined treatment regimes. Despite this, cisplatin and its analogues are extremely toxic and although some patients benefit substantially from treatment, a large proportion suffer the toxic side effects without any therapeutic benefit. Nucleotide excision repair (NER) is a versatile DNA repair system that recognises DNA damage induced by platinum based therapy. For many years the components of the NER pathway have been studied to determine mRNA and protein expression levels in response or resistance to cisplatin in many forms of cancer; particularly testicular, ovarian and NSCLCs. Despite the consistent finding that over or under expression of subsets of NER proteins and mRNA highly correlate with response to cisplatin, the translation of these findings into the clinical setting has not been forthcoming. This review summarises the results of previous investigations into NER in cisplatin response and clinical trials where the expression of NER proteins were compared to the response to platinum therapies in treatment.

Polymorphisms in XPD gene could predict clinical outcome of platinum-based chemotherapy for non-small cell lung cancer patients: a meta-analysis of 24 studies

OBJECTIVE

Xeroderma pigmentosum group D (XPD) is an essential gene involved in the nucleotide excision repair (NER) pathway. Two commonly studied single nucleotide polymorphisms (SNPs) of XPD (Lys751Gln, A>C, rs13181; Asp312Asn, G>A, rs1799793) are implicated in the modulation of DNA repair capacity, thus related to the responses to platinum-based chemotherapy. Here we performed a meta-analysis to better evaluate the association between the two XPD SNPs and clinical outcome of platinum-based chemotherapy in non-small cell lung cancer (NSCLC) patients.

METHODS

A comprehensive search of PubMed database was conducted to identify relevant articles. Primary outcomes included objective response (i.e., complete response + partial response vs. stable disease + progressive disease), progression-free survival (PFS) and overall survival (OS). The pooled and 95% confidence intervals (CIs) of ORs (odds ratios) and HRs (hazard ratios) were estimated using the fixed or random effect model.

RESULTS

Twenty-four studies were eligible according to the inclusion criteria. None of the XPD Lys751Gln/Asp312Asn polymorphisms was associated with objective response, PFS or OS in NSCLC patients treated with platinum drugs. However, in stratified analysis by ethnicity, the XPD Lys751Gln (A>C) polymorphism was not significantly associated with increased response in Caucasians (OR=1.35, 95%CI=1.0-1.83, P=0.122 for heterogeneity) but was associated with decreased PFS in Asians (HR=1.39, 95%CI=1.07-1.81, P=0.879 for heterogeneity). Furthermore, a statistically significant difference existed in the estimates of effect between the two ethnicities (P=0.014 for TR; P<0.001 for PFS).

CONCLUSIONS

XPD Lys751Gln (A>C) may have inverse predictive and prognostic role in platinum-based treatment of NSCLC according to different ethnicities. Further studies are needed to validate our findings.

Customizing chemotherapy in thoracic malignancies based on ERCC1 expression

SUMMARY Platinum-based chemotherapy regimens using cisplatin or carboplatin are the cornerstones of treatment for advanced non-small-cell lung cancer (NSCLC), small-cell lung cancer and malignant pleural mesothelioma. Despite being standard regimens of choice in the majority of patients without oncogene driver mutations, the activity obtained by individual patients varies considerably. Hence, biomarkers such as ERCC1 are needed to predict sensitivity to drugs, which has been explored as a predictor for platinum sensitivity in thoracic malignancies, mostly in the case of NSCLC. ERCC1 may be measured by mRNA activity; however, most studies have examined protein expression via immunohistochemistry. High ERCC1 expression has been a good prognostic factor in resected NSCLC patients who are not receiving chemotherapy, while it has been an adverse predictor for the effect of cisplatin or carboplatin. The latter has also been shown in malignant pleural mesothelioma. Heterogeneous distribution of ERCC1 within tumors may be a source of discordance in the results obtained in various studies. Adding to the discordance may be the fact that there are four isoforms of ERCC1 and seemingly only one of these accounts for cisplatin sensitivity. It is possible that the antibodies used may be equally specific for the same isoforms, which contributes to the heterogeneity of results, in addition to the contribution from immunohistochemistry cutoff levels. Robust evidence in support of the use of ERCC1 to select treatment on an individual patient basis is lacking, and such results from ongoing trials are eagerly awaited in order to improve the possibilities for individualized chemotherapy with improved outcomes.

Correlation of genes associated with drug response to prognosis of large cell lung carcinoma

Platinum-based chemotherapy remains the main treatment of advanced lung cancer. However, platinum resistance has become a major treatment obstacle. Novel therapies, particularly tyrosine kinase inhibitors of the epidermal growth factor receptor (EGFR-TKI) and agents that target vascular endothelial growth factor (VEGF), have improved the treatment. Both chemotherapy and targeted therapy have their molecular mechanisms. This study aimed to determine the mutation, amplification, or expression status and interrelationships of the epidermal growth factor receptor (EGFR), K-Ras proto-oncogene, excision repair cross-complementation group 1 (ERCC1), and VEGF genes as well as their correlations to prognosis of large cell lung carcinoma (LCLC) after EGFR-targeted therapy, chemotherapy, and anti-VEGF therapy. EGFR and K-Ras mutations in 60 specimens of LCLC were detected by direct DNA sequencing. EGFR, ERCC1, and VEGF protein expression was detected by immunohistochemistry (IHC). EGFR gene copy number was detected by fluorescence in situ hybridization (FISH). One (1.7%) patient had an EGFR L858M point mutation in exon 21, 3 (5.0%) had K-Ras mutations, and 10 (19.6%) had EGFR amplification (FISH positive). Positive rates of EGFR, ERCC1, and VEGF proteins were 38.3%, 56.7%, and 70.0%, respectively. EGFR amplification was positively correlated to EGFR protein expression (r = 0.390, P = 0.005). The positive rate of VEGF protein was significantly higher in patients with lymph node metastasis than in those without (84.6% vs. 58.8%, P = 0.046). No significant correlations were observed among the EGFR, K-Ras, ERCC1, and VEGF genes. EGFR gene amplification and the low rate of EGFR mutation suggest that patients with LCLC are likely to obtain little benefit from anti-EGFR therapies.

Predictive impact of RRM1 protein expression on vinorelbine efficacy in NSCLC patients randomly assigned in a chemotherapy phase III trial

BACKGROUND

Platinum-based doublets (PBDs) remain the cornerstone of treatment in non-small-cell lung cancer (NSCLC) and may include gemcitabine. A biomarker predicting sensitivity to this antimetabolite would represent a major step forward. Accordingly, we explored the predictive role of ribonucleotide reductase subunit M (RRM1) in advanced NSCLC.

PATIENTS AND METHODS

A total of 443 patients were randomly assigned to regimen A [paclitaxel (Taxol) and cisplatin with gemcitabine] or regimen B (cisplatin and vinorelbine). Immunohistochemical evaluation of RRM1 was correlated to clinical end-points.

RESULTS

A total of 261 (58.9%) patients had representative tissue samples for RRM1 evaluation. Disease control rate, progression-free survival (PFS) and overall survival (OS) were substantially improved in patients with RRM-negative (neg) tumors receiving regimen B when compared with patients with RRM-positive (pos) tumors (68.8% versus 31.2%, P = 0.046, 6.90 months versus 3.93 months, P = 0.000 and 11.57 months versus 7.4 months, P = 0.002, respectively). Interaction analysis between RRM1-neg status and adenocarcinomas yielded a hazard ratio (HR) of 0.36 for death (P = 0.000).

CONCLUSIONS

RRM1 protein expression was without any predictive impact in patients treated with cisplatin, paclitaxel and gemcitabine. Surprisingly, the predictive power was demonstrated in the cisplatin and vinorelbine arm and may suggest that RRM1 is involved in vinorelbine sensitivity warranting further research.

ERCC1 expression as a prognostic and predictive factor in patients with non-small cell lung cancer: a meta-analysis

It is hypothesized that high expression of the excision repair cross-complementation group 1 (ERCC1) gene might be a positive prognostic factor, but predict decreased sensitivity to platinum-based chemotherapy. Results from the published data are inconsistent. To derive a more precise estimation of the relationship between ERCC1 and the prognosis and predictive response to chemotherapy of non-small cell lung cancer (NSCLC), a meta-analysis was performed. An electronic search of the PubMed and Embase database was performed. Hazard ratio (HR) for overall survival (OS) was pooled in early stage patients received surgery alone to analyze the prognosis of ERCC1 on NSCLC. HRs for OS in patients received surgery plus adjuvant chemotherapy and in patients received palliative chemotherapy and relative risk (RR) for overall response to chemotherapy were aggregated to analyze the prediction of ERCC1 on NSCLC. The pooled HR indicated that high ERCC1 levels were associated with longer survival in early stage patients received surgery alone (HR, 0.69; 95% confidence interval (CI), 0.58-0.83; P = 0.000). There was no difference in survival between high and low ERCC1 levels in patients received surgery plus adjuvant chemotherapy (HR, 1.41; 95% CI, 0.93-2.12; P = 0.106). However, high ERCC1 levels were associated with shorter survival and lower response to chemotherapy in advanced NSCLC patients received palliative chemotherapy (HR, 1.75; 95% CI, 1.39-2.22; P = 0.000; RR, 0.77; 95% CI, 0.64-0.93; P = 0.007; respectively). The meta-analysis indicated that high ERCC1 expression might be a favourable prognostic and a drug resistance predictive factor for NSCLC.

Effect of polymorphisms in XPD on clinical outcomes of platinum-based chemotherapy for Chinese non-small cell lung cancer patients

PURPOSE

Xeroderma pigmentosum group D (XPD) codes for a DNA helicase involved in nucleotide excision repair that removes platinum-induced DNA damage. Genetic polymorphisms of XPD may affect DNA repair capacity and lead to individual differences in the outcome of patients after chemotherapy. This study aims to identify whether XPD polymorphisms affect clinical efficacy among advanced non-small cell lung cancer (NSCLC) patients treated with platinum-based chemotherapy.

EXPERIMENTAL DESIGN

353 stage III-IV NSCLC patients receiving platinum-based chemotherapy as the first-line treatment were enrolled in this study. Four potentially functional XPD polymorphisms (Arg(156)Arg, Asp(312)Asn, Asp(711)Asp and Lys(751)Gln) were genotyped by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry or PCR-based sequencing.

RESULTS

Variant genotypes of XPD Asp(312)Asn, Asp(711)Asp and Lys(751)Gln were significantly associated with poorer NSCLC survival (P = 0.006, 0.006, 0.014, respectively, by log-rank test). The most common haplotype GCA (in order of Asp(312)Asn, Asp(711)Asp and Lys(751)Gln) also exhibited significant risk effect on NSCLC survival (log-rank P = 0.001). This effect was more predominant for patients with stage IIIB disease (P = 2.21×10(-4), log-rank test). Increased risks for variant haplotypes of XPD were also observed among patients with performance status of 0-1 and patients with adenocarcinoma. However, no significant associations were found between these polymorphisms, chemotherapy response and PFS.

CONCLUSIONS

Our study provides evidence for the predictive role of XPD Asp(312)Asn, Asp(711)Asp and Lys(751)Gln polymorphisms/haplotype on NSCLC prognosis in inoperable advanced NSCLC patients treated with platinum-based chemotherapy.

The role of βIII-tubulin in non-small cell lung cancer patients treated by taxane-based chemotherapy

BACKGROUND

The aim of this study is to evaluate whether class III β-tubulin (TUBB3) expression could predict progression-free survival or overall survival in relapsed non-small cell lung cancer (NSCLC) patients treated with taxene-based chemotherapy.

METHODS

Immunohistochemistal staining was used to examine the expression of TUBB3 in resected lung tumor specimens obtained from 56 patients treated with platinum-based chemotherapy against recurrent tumors after curative resections. Excision repair cross-complementation group 1, breast cancer susceptibility gene 1, vascular endothelial growth factor, Ki-67, CD34, and p53 were also correlated with clinical features and outcome after treatment.

RESULTS

Of the 56 patients enrolled in the study, 29 were treated by carboplatin plus paclitaxel as first-line treatment, and 24 patients received docetaxel monotherapy as second- or third-line treatment. A positive TUBB3 expression is closely associated with a poor response to taxane-based chemotherapy. TUBB3 expression was an independent prognostic factor for predicting poor progression-free survival after docetaxel administration. However, TUBB3 expression could not predict outcome after carboplatin plus paclitaxel treatment. The other biomarkers tested were not independent prognostic factors for predicting outcome after taxane-based chemotherapy.

CONCLUSION

TUBB3 expression is associated with resistance to taxane-based chemotherapy and is an independent prognostic factor for predicting poor progression-free survival after docetaxel treatment alone. TUBB3 expression may be a predictive marker for chemoresistance to docetaxel in NSCLC with postoperative recurrent disease.

The relationship between ERCC1 expression and clinical outcome in patients with FIGO stage I to stage II uterine cervical adenocarcinoma

OBJECTIVE

Several studies have suggested that excision repair cross-complementation group 1 (ERCC1), a protein involved in nucleotide excision repair, is associated with resistance to platinum agent-based chemotherapy or chemoradiotherapy with platinum agents in various types of cancer. Herein we evaluated ERCC1 protein expression in uterine cervical adenocarcinoma and the relationship between this expression, clinicopathological factors, and clinical outcome, particularly in patients receiving adjuvant cisplatin-based chemotherapy or chemoradiotherapy with cisplatin.

METHODS

Thirty-six patients with International Federation of Gynecology and Obstetrics (FIGO) stage IB to stage IIB cervical adenocarcinoma who underwent radical hysterectomy were evaluated. Excision repair cross-complementation group 1 protein expression was examined by immunohistochemistry in tumor tissues. The relationship between ERCC1 expression levels and clinicopathological factors (age, FIGO stage, histological grade, tumor size, vascular invasion, cervical stromal invasion, and lymph node metastases) and prognosis was evaluated.

RESULTS

No significant differences between ERCC1 expression levels and clinicopathological factors were observed. The patients in the ERCC1 high-expression group (n = 7) experienced significantly worse disease-free survival than the patients in the ERCC1 low-expression group (n = 29; P = 0.005). Among the 25 patients who received cisplatin-based chemotherapy or chemoradiotherapy with cisplatin, those with high ERCC1 expression (n = 5) also experienced significantly worse disease-free survival than those with low ERCC1 expression (n = 20; P = 0.002). Moreover, univariate and multivariate analyses revealed that high ERCC1 expression was an independent prognostic factor in patients receiving cisplatin-based chemotherapy or chemoradiotherapy with cisplatin.

CONCLUSIONS

This is the first analysis of the association between ERCC1 expression and clinical outcomes in patients with uterine cervical adenocarcinoma. High ERCC1 protein expression was revealed to be associated with worse disease-free survival in the patients who received adjuvant cisplatin-based chemotherapy or chemoradiotherapy with cisplatin and was shown to be an independent prognostic factor. Further evaluation with a larger number of patients is required to confirm these preliminary observations.

Excision repair cross-complementation group 1 (ERCC1) status and lung cancer outcomes: a meta-analysis of published studies and recommendations

Purpose

Despite discrepant results on clinical utility, several trials are already prospectively randomizing non-small cell lung cancer (NSCLC) patients by ERCC1 status. We aimed to characterize the prognostic and predictive effect of ERCC1 by systematic review and meta-analysis.

Methods

Eligible studies assessed survival and/or chemotherapy response in NSCLC or SCLC by ERCC1 status. Effect measures of interest were hazard ratio (HR) for survival or relative risk (RR) for chemotherapy response. Random-effects meta-analyses were used to account for between-study heterogeneity, with unadjusted/adjusted effect estimates considered separately.

Results

23 eligible studies provided survival results in 2,726 patients. Substantial heterogeneity was observed in all meta-analyses (I² always >30%), partly due to variability in thresholds defining ‘low’ and ‘high’ ERCC1. Meta-analysis of unadjusted estimates showed high ERCC1 was associated with significantly worse overall survival in platinum-treated NSCLC (average unadjusted HR = 1.61, 95%CI:1.23–2.1, p = 0.014), but not in NSCLC untreated with chemotherapy (average unadjusted HR = 0.82, 95%CI:0.51–1.31). Meta-analysis of adjusted estimates was limited by variable choice of adjustment factors and potential publication bias (Egger's p<0.0001). There was evidence that high ERCC1 was associated with reduced response to platinum (average RR = 0.80; 95%CI:0.64–0.99). SCLC data were inadequate to draw firm conclusions.

Conclusions

Current evidence suggests high ERCC1 may adversely influence survival and response in platinum-treated NSCLC patients, but not in non-platinum treated, although definitive evidence of a predictive influence is lacking. International consensus is urgently required to provide consistent, validated ERCC1 assessment methodology. ERCC1 assessment for treatment selection should currently be restricted to, and evaluated within, clinical trials.

Alterations of microRNAs in cisplatin-resistant human non-small cell lung cancer cells (A549/DDP)

ABSTRACT MicroRNAs (miRNAs) are a class of small, noncoding RNAs that posttranscriptionally regulate genes expression and play crucial roles in diverse biological processes, such as development, differentiation, apoptosis, and proliferation. Accumulating evidence suggests that miRNAs may play a role in chemoresistance and may be involved in the modulation of some drug resistance-related pathways in cancer cells. Here, the authors investigated the possible role of miRNAs in the development of drug resistance in lung cancer cell line. The results showed that 14 miRNAs were presented significantly (>2-fold), including up-regulation of 9 miRNAs and down-regulation of 5 miRNAs in A549/DDP cell line, compared with the parental A549 cell line. Up-regulation of miR-138 increased the sensitivity of A549/DDP cells to cisplatin in in vitro drug sensitivity assay, and increased apoptosis assessed by flow cytometry. The authors also found that excision repair cross-complementation group 1 (ERCC1) was negatively regulated by miR-138 and that down-regulation of ERCC1 at the protein level largely correlated with elevated levels of miR-138 in A549/DDP cells. Taken together, these findings suggest that miR-138 could play an important role in the development of cisplatin resistance in non-small cell lung cancer (NSCLC).

ERCC1 and XRCC1 as biomarkers for lung and head and neck cancer

Advanced stage non-small cell lung cancer and head and neck squamous cell carcinoma are both treated with DNA damaging agents including platinum-based compounds and radiation therapy. However, at least one quarter of all tumors are resistant or refractory to these genotoxic agents. Yet the agents are extremely toxic, leading to undesirable side effects with potentially no benefit. Alternative therapies exist, but currently there are no tools to predict whether the first-line genotoxic agents will work in any given patient. To maximize therapeutic success and limit unnecessary toxicity, emerging clinical trials aim to inform personalized treatments tailored to the biology of individual tumors. Worldwide, significant resources have been invested in identifying biomarkers for guiding the treatment of lung and head and neck cancer. DNA repair proteins of the nucleotide excision repair pathway (ERCC1) and of the base excision repair pathway (XRCC1), which are instrumental in clearing DNA damage caused by platinum drugs and radiation, have been extensively studied as potential biomarkers of clinical outcomes in lung and head and neck cancers. The results are complex and contradictory. Here we summarize the current status of single nucleotide polymorphisms, mRNA, and protein expression of ERCC1 and XRCC1 in relation to cancer risk and patient outcomes.

Molecular predictors of response to chemotherapy in non-small cell lung cancer

Lung cancer is the leading cause of cancer-related mortality in the United States with 222,520 new cases and 157,300 deaths anticipated in 2010. The primary objective of any cancer treatment is to improve patient outcomes including overall survival and quality of life while minimizing treatment toxicity. As our knowledge of the molecular mechanisms involved in the pathogenesis of lung cancer evolves, improved methods of therapeutic selection may help clinicians better realize these goals. Such selection may be accomplished by examining biomarkers within patients' tumors that may provide prognostic information such as risk of recurrence in early stage disease or predict benefit from specific therapies regardless of disease stage. Three such biomarkers have emerged--excision repair cross-complementation group 1, the regulatory subunit of the ribonucleotide reductase enzyme, and thymidylate synthase--and are actively being evaluated in patients with non-small cell lung cancer. This review will focus on the role of these biomarkers as predictive and/or prognostic markers in the selection of chemotherapy regimens in non-small cell lung cancer patients.

Synergistic effect of curcumin and cisplatin via down-regulation of thymidine phosphorylase and excision repair cross-complementary 1 (ERCC1)

Curcumin (diferuloylmethane), a phenolic compound obtained from the rhizome of Curcuma longa, is known to have antiproliferative and antitumor properties. Thymidine phosphorylase (TP), an enzyme of the pyrimidine salvage pathway, is considered an attractive therapeutic target, and its expression could suppress cancer cell death induced by DNA damage agents. Excision repair cross-complementary 1 (ERCC1) is a protein involved the process of nucleotide excision repair. The ERCC1 gene is expressed at high levels in cancers and has been associated with resistance to platinum-based chemotherapy. In this study, the effects of curcumin on TP and ERCC1 expression induced by cisplatin in non-small-cell lung cancer (NSCLC) cell lines was investigated. Exposure of the NSCLC cells to various concentrations of curcumin (5-40 μM) down-regulates the mRNA and protein levels of TP and ERCC1 through destabilization of the mRNA and proteins via a mechanism involving inactivation of MKK1/2-extracellular signal-regulated kinase (ERK1/2). Depletion of endogenous TP or ERCC1 expression by transfection with specific small interfering RNAs significantly decreases cell viability in curcumin-exposed NSCLC cells. Curcumin enhances the sensitivity of cisplatin treatment for NSCLC through inactivation of ERK1/2 and by decreasing the TP and ERCC1 protein levels. Enhancement of ERK1/2 signaling by constitutively active MKK1/2 causes an increase in TP and ERCC1 protein levels and promotes cell viability after cotreatment with curcumin and cisplatin. Enhancement of the cytotoxicity to cisplatin by administration of curcumin is mediated by down-regulation of the expression levels of TP and ERCC1 and by inactivation of ERK1/2.

Expression of ERCC1 and its clinicopathological correlations in non-small cell lung cancer

Excision Repair Cross-Complementing Group 1 (ERCC1) is an important DNA repair gene, playing critical role in nucleotide excision repair pathway and having a significant influence on genomic instability. Some studies support that ERCC1 might be a potential predictive and prognostic marker in non-small cell lung cancer (NSCLC). ERCC1 has also been shown to be a promising biomarker in NSCLC treated with a cisplatin-based regimen. Therefore, the determination of ERCC1 expression at DNA, mRNA and protein level in different stages of NSCLC is still an important topic in the cancer. Ninety-one formalin-fixed paraffin-embedded tumor samples histopathologically diagnosed as NSCLC were examined in this study. ERCC1 expression at protein level were scored by immunohistochemistry. The gene amplification and mRNA expression levels for ERCC1 were determined by real-time quantitative PCR. There was complete concordance among the three methods in 39 tumor samples (42.9%). A strong correlation was found between DNA amplification and mRNA expression (r=0.662) while there was no correlation between mRNA and protein assessment for ERCC1 expression (r=-0.013). ERCC1 expression at mRNA and DNA level (63.1 and 84.2%, respectively) in tumors at stage III was higher than at the other stages. In contrast, the protein expression at stage II and III (56.6 and 52.6%, respectively) of NSCLC was lower than that of tumors with stage I NSCLC. These results show that the mechanism by which ERCC1 expression might play a role in tumor behavior. This study was also confirmed that the appropriate validation and qualification in methods used for ERCC1 status were needed before its clinical application and implementation.

Nucleotide excision repair polymorphisms and survival outcome for patients with metastatic breast cancer

PURPOSE

Inter-individual variations in treatment efficacy may be influenced by polymorphisms in DNA repair genes. We investigated the association of 3 functional polymorphisms in the nucleotide excision repair (NER) pathway with survival outcome of 95 patients with metastatic breast cancer (MBC) treated with DNA-damaging chemotherapy.

METHODS

ERCC1 8092 C/A, ERCC2 Asp312Asn and ERCC2 Lys751Gln were determined using Taqman-based genotyping assays. Genotype associations with breast cancer-specific survival (BCSS) and progression-free survival (PFS) were evaluated using Kaplan-Meier estimates and hazard ratios calculated using Cox regression analysis. Tests for trend were conducted by calculating P-values for the HR coefficient in proportional hazards regression models.

RESULTS

ERCC2 Lys751Gln was significantly associated with BCSS (median: 24.8 months for AA/AC combined and 14.2 months for CC, HR: 1.9 (95% CI 1.06-3.26)). Median BCSS decreased with increasing number of designated adverse genotypes for the 3 polymorphisms (P (trend) = 0.003). Risk estimates for PFS were nonsignificantly elevated and were significantly elevated for BCSS for patients with 2 (HR = 2.21, 95% CI: 1.04-4.72) or 3 (HR = 6.67, 95% CI: 2.19-20.29) adverse genotypes. In treatment subgroup analysis, risk estimates for BCSS were significantly elevated for patients with 3 adverse genotypes treated with cyclophosphamide, mitoxantrone and vinblastine (HR: 11.9, 95% CI 1.77-79.51) and P (trend) = 0.02 for increasing number of adverse genotypes. Risk of progression was significantly increased for patients with 1 adverse genotype treated with cyclophosphamide, mitoxantrone and carboplatin (HR: 3.5, 95% CI 1.19-10.6) and P (trend) = 0.02 for increasing number of adverse genotypes.

CONCLUSION

Polymorphisms in NER pathway may impact survival outcome for patients with MBC following treatment with DNA-damaging chemotherapy. These results provide support for a polygenic pathway approach for assessing the prognostic and predictive potential of polymorphisms in treatment outcome.

Prognostic significance of ERCC1 expression in resected non small cell lung carcinoma

BACKGROUND AND AIM

The effects of DNA repair pathway on survival were assessed by measuring the tumoral excision repair cross complementation 1 (ERCC1) expression in patients with resected non-small cell lung carcinoma (NSCLC). We aimed to determine the prognostic and predictive significance of ERCC1 in patients with completely resected NSCLC.

METHODS

Immunohistochemistry (IHC) was used to assess the expression of ERCC1 in resected lung tumor samples obtained from 98 patients untreated without pre- or post-operative chemotherapy and/or radiotherapy. The median H score was used as a cut-off for ERCC1 IHC. Univariate and multivariate analyses were performed for factors influencing patient survival.

RESULTS

The 5-year survival rates of patients for ERCC1 positive expression and ERCC1 negative expression were 76% and 49%, respectively; this difference was statistically significant (p = 0.004). Subsequent multivariate analysis suggested that ERCC1 expression (adjusted hazard ratio for death, 0.38; 95% CI, 0.18 to 0.78; p = 0.008) and pathological stage (2.2; 95% CI, 1.09 to 4.5; p = 0.027) were both independent prognostic factors.

CONCLUSION

The level of ERCC1 expression in tumors a strong predictor of survival in resected NSCLC patients untreated without pre- or post-operative chemotherapy and/or radiotherapy.

Modulation of Rad51, ERCC1, and thymidine phosphorylase by emodin result in synergistic cytotoxic effect in combination with capecitabine

Thymidine phosphorylase (TP) is the rate-limiting enzyme for the activation of capecitabine (pro-drug of fluorouracil), and as a useful predictor of tumor response to capecitabine-based chemotherapy. Overexpression of Rad51 and ERCC1 induce resistance to chemotherapeutic agents. Emodin, one of the main bioactive anthraquinone derivatives in the roots and rhizomes of numerous plants, possesses potent antitumor effects. Accordingly, we aimed to explore the molecular mechanism of emodin enhances the capecitabine-induced cytotoxicity through controlling Rad51, ERCC1, and TP expression in human non-small cell lung cancer (NSCLC). The results show that capecitabine increases the phosphorylation of MKK1/2-ERK1/2 and protein levels of Rad51 and ERCC1 through enhancing the protein stability. Depletion of endogenous Rad51 or ERCC1 expression by specific small interfering RNA transfection significantly increases capecitabine-induced cell death and growth inhibition. Emodin enhances the capecitabine-induced cytotoxic effects through ERK1/2 inactivation and decreasing the Rad51 and ERCC1 protein levels induced by capecitabine. Enhancement of ERK1/2 signaling by constitutively active MKK1/2 (MKK1/2-CA) results in increasing Rad51 and ERCC1 protein levels and cell viability in NSCLC cell lines treated with emodin and capecitabine. Interestingly, emodin enhances TP mRNA and protein expression in capecitabine treated NSCLC cell lines, and depletion of the TP expression decreases the cytotoxic effects induced by capecitabine and emodin. We conclude that enhancing the cytotoxicity to capecitabine by emodin is mediated by down-regulation the expression of Rad51 and ERCC1 and up-regulation TP expression.

ERCC1 Expression Analysis to Guide Therapy in Non-Small Cell Lung Cancer

Worldwide, lung cancer accounts for approximately 1 million deaths each year, making it the most common cause of cancer-related mortality. Non-small cell lung cancer (NSCLC) accounts for approximately 85% of lung cancer cases and is often associated with a relatively poor prognosis. The majority of NSCLC patients present with advanced disease and have an average 5-year survival rate of 5%. Currently, the standard of care for NSCLC includes treatment with a platinum-based chemotherapy regimen. However, not all patients benefit equally from such treatment. Therefore, recent pharmacogenomic studies have been performed in order to identify specific biomarkers that may allow for patient-tailored treatment strategies. One such biomarker is expression of the excision repair cross-complementation group 1 protein, ERCC1.

Tumor and host factors that may limit efficacy of chemotherapy in non-small cell and small cell lung cancer

While chemotherapy provides useful palliation, advanced lung cancer remains incurable since those tumors that are initially sensitive to therapy rapidly develop acquired resistance. Resistance may arise from impaired drug delivery, extracellular factors, decreased drug uptake into tumor cells, increased drug efflux, drug inactivation by detoxifying factors, decreased drug activation or binding to target, altered target, increased damage repair, tolerance of damage, decreased proapoptotic factors, increased antiapoptotic factors, or altered cell cycling or transcription factors. Factors for which there is now substantial clinical evidence of a link to small cell lung cancer (SCLC) resistance to chemotherapy include MRP (for platinum-based combination chemotherapy) and MDR1/P-gp (for non-platinum agents). SPECT MIBI and Tc-TF scanning appears to predict chemotherapy benefit in SCLC. In non-small cell lung cancer (NSCLC), the strongest clinical evidence is for taxane resistance with elevated expression or mutation of class III beta-tubulin (and possibly alpha tubulin), platinum resistance and expression of ERCC1 or BCRP, gemcitabine resistance and RRM1 expression, and resistance to several agents and COX-2 expression (although COX-2 inhibitors have had minimal impact on drug efficacy clinically). Tumors expressing high BRCA1 may have increased resistance to platinums but increased sensitivity to taxanes. Limited early clinical data suggest that chemotherapy resistance in NSCLC may also be increased with decreased expression of cyclin B1 or of Eg5, or with increased expression of ICAM, matrilysin, osteopontin, DDH, survivin, PCDGF, caveolin-1, p21WAF1/CIP1, or 14-3-3sigma, and that IGF-1R inhibitors may increase efficacy of chemotherapy, particularly in squamous cell carcinomas. Equivocal data (with some positive studies but other negative studies) suggest that NSCLC tumors with some EGFR mutations may have increased sensitivity to chemotherapy, while K-ras mutations and expression of GST-pi, RB or p27kip1 may possibly confer resistance. While limited clinical data suggest that p53 mutations are associated with resistance to platinum-based therapies in NSCLC, data on p53 IHC positivity are equivocal. To date, resistance-modulating strategies have generally not proven clinically useful in lung cancer, although small randomized trials suggest a modest benefit of verapamil and related agents in NSCLC.

ERCC1 and Ki67 in small cell lung carcinoma and other neuroendocrine tumors of the lung: distribution and impact on survival

BACKGROUND

Excision repair cross-complementation group 1 (ERCC1) is a key component of the platinum-DNA repair mechanism. Ki67 is associated with the clinical course of several malignancies. The associations of ERCC1 and Ki67, clinical features and survival in small cell lung carcinoma (SCLC), typical carcinoid (TC), atypical carcinoid (AC), and large cell neuroendocrine carcinoma (LCNEC) were determined.

MATERIALS AND METHODS

We included a consecutive series of 186 patients with SCLC treated with platinum-based chemotherapy and surgically treated patients with TC (n = 48), AC (n = 15) and LCNEC (n = 27). ERCC1 and Ki 67 were measured by immunohistochemistry and scored using published criteria.

RESULTS

The expression of ERCC1 was different among the different tumor types (p < 0.001). For patient with limited disease as well as extensive disease SCLC, no association of ERCC1 expression with survival was observed (p = 0.59). However, only 10% of SCLC tumors expressed ERCC1. For TC and AC, ERCC1 positive patients had better survival than ERCC1 negative patients. ERCC1 had no prognostic impact for LCNEC. A difference of the percentage of Ki67 LI was observed for the different tumor types (p < 0.001). The difference between TC and AC was significant (p = 0.02), as was the difference between low grade (TC+AC) and high grade NE (LCNEC + SCLC) (p < 0.001). For all included patients, a correlation between Ki67 and ERCC1 was observed (RSquare = 0.19, p < 0.001).

CONCLUSION

ERCC1 expression in SCLC treated with platinum-based chemotherapy has no impact on survival. High expression of ERCC1 in TC might represent a clue to the failure of platinum-based therapy in these patients. ERCC1 expression has prognostic impact in lung carcinoids. Ki 67 might be considered as a supplementary test to the histopatologic classification of NE tumors.

Downregulation of XPF-ERCC1 enhances cisplatin efficacy in cancer cells

Bulky cisplatin lesions are repaired primarily by nucleotide excision repair (NER), in which the structure specific endonuclease XPF-ERCC1 is a critical component. It is now known that the XPF-ERCC1 complex has repair functions beyond NER and plays a role in homologous recombination (HR). It has been suggested that expression of ERCC1 correlates with cisplatin drug resistance in non-small cell lung cancer (NSCLC). In our study, using NSCLC, ovarian, and breast cancer cells, we show that the XPF-ERCC1 complex is a valid target to increase cisplatin cytotoxicity and efficacy. We targeted XPF-ERCC1 complex by RNA interference and assessed the repair capacity of cisplatin intrastrand and interstrand crosslinks by ELISA and alkaline comet assay, respectively. We also assessed the repair of cisplatin-ICL-induced double-strand breaks (DSBs) by monitoring gamma-H2AX focus formation. Interestingly, XPF protein levels were significantly reduced following ERCC1 downregulation, but the converse was not observed. The transcript levels were unaffected suggesting that XPF protein stability is likely affected. The repair of both types of cisplatin-DNA lesions was decreased with downregulation of XPF, ERCC1 or both XPF-ERCC1. The ICL-induced DSBs persist in the absence of XPF-ERCC1. The suppression of the XPF-ERCC1 complex significantly decreases the cellular viability which correlates well with the decrease in DNA repair capacity. A double knockdown of XPF-ERCC1 displays the greatest level of cellular cytotoxicity when compared with XPF or ERCC1 alone. The difference in cytotoxicity observed is likely due to the level of total protein complex remaining. These data demonstrate that XPF-ERCC1 is a valid target to enhance cisplatin efficacy in cancer cells by affecting cisplatin-DNA repair pathways.